Traditionally, disperse dyes are used for dyeing synthetic fibers and its blend with other fibers such as cellulose, polyurethane, nylon and wool by usual exhaust dyeing, continuous dyeing and printing techniques.
Indian Patent application 2162/KOLNP/2009 which is the Indian Equivalent of WO2008074719 and entitled “Disperse dye mixtures” discloses mixtures of disperse azo dyes with anthraquinone or benzodifuranone dyes for the colouration of synthetic textile materials. The said patent emphasizes on the disperse dyes mixtures to achieve desired fastness properties.
Indian Patent number: IN 190551 (1700/DEL/94) which is the Indian equivalent of WO950200014 relates to monoazo dyes and a process for colouring synthetic textile materials, to synthetic textiles when coloured, to a process for the mass coloration of plastics, to plastics when coloured, to certain novel azo dyes and to compositions containing azo dyes. IN197577 (935/DEL/2002) and IN196765 (936/DEL/2002), divisional to Patent no: IN 190551 also teach process for the preparation of an azo dye compound.
Recently with changing trends, fashion and market requirement consumption of blended fabrics is significantly increased. These new fabrics are made out of micro size fiber using fine denier polyester fiber or blending fiber with polyurethane, nylon and wool. The fastness properties of these new colored fabrics become worse with respect to light fastness and sublimation fastness, particularly washing fastness when dyed or printed with conventional disperse dyes.
To overcome limitations of light fastness and washing fastness in disperse dyes for synthetic textiles, the inventors of the present invention we have developed range of disperse dyes with excellent overall fastness properties particularly washing fastness.